Perpetual Inertia

The Australian composer Peter McNamara wrote Perpetual Inertia especially for the NJO ensemble of the 21st century. The physical concept of eternal inertia, or ‘infinite energy’ in the words of McNamara, formed the inspiration for the work. This concept can be heard in the music through a very vigorous and rhythmic gesture in the dynamics. In the beginning this is noticeable by rapid movement between loud and soft on the note ‘E’. This motif develops during the course of the piece on other tones and with different rhythmic proportions between dynamics.

Perpetual Inertia is a composition in which McNamara uses aspects of techniques from spectral composers such as Tristan Murail and Gérard Grisey. In spectral music, tones are layered by the ensemble as a result of an overtone range based on a spectrogram, which is a graph on which a sound in frequencies against time is represented. Since each instrument possesses its own overtone structure a new, frequently very complex timbre results. One of the composition techniques of spectralism borrowed by McNamara is a technique where the pitches of an overtone range are gradually compressed closer to each other.